The Great Oxygen Event marks the time, approximately 2.5 billion years ago, when ________.

there was enough oxygen in the atmosphere to support a major burst of life on Earth

there was a cataclysmic weather event that absorbed most of the oxygen in the atmosphere and locked it into iron deposits in the oceans

there was significant oxygen in the atmosphere

there was a massive volcanic eruption that lead to a very rapid increase in oxygen levels on Earth

photosynthesis was clearly established and producing oxygen.

The Great Oxygen Event marks the time, approximately 2.5 billion years ago, when there was enough oxygen in the atmosphere to support a major burst of life on Earth

For the first half of the Earht's history, there was no oxygen in the atmosphere. It was inhabited only by single-celled organisms.Of those simple life forms, the cyanobacteria may have. evolved a way to take energy from sunlight, and used it to make sugars out of water and carbon dioxide. They used the same chemical process we know as photosynthesis. This released vast quantities of oxygen into the atmosphere and triggered the evolution of complex life.

shivjimishraVT shivjimishraVT · Answer 2 · 2022-03-05T05:10:33+01:00

The Great Oxygen event marks the time, approximately 2.5 billion years ago when photosynthesis was clearly established and producing oxygen.

What is the Great Oxygen event?

The Great Oxygen event has occurred when cyanobacteria (blue-green algae) living in the oceans started producing oxygen through photosynthesis.

Oxygen level was increased in the atmosphere due to the release of oxygen during photosynthesis by such prokaryotes. With this activity by cyanobacteria, the environment gets oxidizing which is reduced initially.

Therefore, photosynthesis was clearly established and produced oxygen in the great oxygen event that takes place approximately 2.5 billion years ago.

To learn more about the Great oxygen event, refer to the link:

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